EQA1989E Invalid session ID - session_ID

Explanation

Conversation initialization failed due to an invalid session ID in the Session Parameter. There could be several reasons for this,
  1. The session ID is longer than 8 characters or contains invalid characters. Valid session IDs consist of 1-8 alphanumeric characters.
  2. There is already another PWS z/OS® Debugger session with the given session ID.

Programmer response

Diagnostic information is recorded in either the EVFERROR.LOG or the EQALU62.LOG. The path where these logs are stored is in the CODETMPDIR environment variable in CONFIG.SYS. If there is already an existing PWS z/OS Debugger session with the given session ID then a different session ID must be provided for concurrent debug sessions on the same workstation. If a session ID is not specified, it defaults to CODEDT. For a description of the Session Parameter and its contents, see the z/OS Debugger manual.